Jessica Biel

Biel may have married the guy we've all crushed on since middle school, but she still has plenty in common with the rest of us—like embarrassing period memories, as she recently told Glamour. She offered refreshingly honest quotes: "I was in a school play, wearing a gray beard and this pad the size of a skateboard and thinking, What is happening to me?" she said. "We want girls to know what their [body is going through] so they don't feel scared or ashamed or gross." And that's precisely why Biel is appearing in educational videos with WomanCare Global, a nonprofit for women's reproductive health. (Find out what Biel had to say about her muscular physique in 20 Celebs Criticized for Their Curves.)

Martina Navratilova

The retired tennis legend told the BBC earlier this year that menstruation affected her on the court. "You don't want to use it as an excuse, but it can affect some players in a big way," she said. "I never talked about it, but it certainly was there." She even estimated that she might have lost her first Wimbledon championship if the final match had taken place one day earlier—a day she spent in bed because of her period. (Use these 6 Ways to Stop Your Menstrual Cycle from Ruining Your Workouts.)

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Jenny Slate

The 33-year-old star of the rom-com "Obvious Child," a movie about unplanned pregnancy, talked sex ed with Glamour last year. "I got great sex education, and I always knew that if I wanted to be sexually active, I had to have safe sex," Slate said. "I think that there's a lot of gray areas and a lot of weird shame that goes into our experience when we first become sexually active. I was saying to a friend last night, I wish I had an experience in college where we could have just sat around and casually talked about our bodies. I was like, 'I'm using my vagina, and I'm using my body in a new way, and I'm just a little bit freaked out by it!' I wish that there had been something more than just a campus health center. Something that made it more normal."

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Angelina Jolie Pitt

In 2013, Jolie Pitt wrote a New York Times op-ed detailing her decision to have a double mastectomy after discovering she carries a gene that increases breast cancer risk. This March, she penned another piece revealing her decision to have her ovaries and fallopian tubes removed due to the same gene and her family history of cancer. "I did not do this solely because I carry the BRCA1 gene mutation, and I want other women to hear this," she wrote. "A positive BRCA test does not mean a leap to surgery. I have spoken to many doctors, surgeons and naturopaths. There are other options. Some women take birth control pills or rely on alternative medicines combined with frequent checks. There is more than one way to deal with any health issue. The most important thing is to learn about the options and choose what is right for you personally." (Learn more about Why Angelina Jolie Pitt's Newest Preventative Surgery Was the Right Decision—for Her.)

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Tyra Banks

The supermodel wants to be a mom and, since she's now 41, has undergone IVF. She recently revealed to People "I've had some not happy moments with that, very traumatic moments," she said. "It's difficult as you get older. It's not something that can just happen." On her new show "FabLife", Banks went further: "It's so funny, when I was 23 years old, I used to tell myself, 'In three years, I'm going to have kids.' Then I turned 24. 'In three years, I'm going to have kids,'" she said. "Every single year I kept saying that. And then after a while it's like, 'Okay, now I want to.' And it's not so easy." (Don't make basic mistakes: Study Shows Half of Women Don't Know Basic Facts About Baby-Making.)

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Kim Kardashian West

We could dedicate a whole website to this woman's quotes. She recently revealed to C Magazine particularly intimate details about her first pregnancy and struggles to conceive again. "I had this condition called placenta accreta," she said, which is when the placenta invades the wall of your uterus and can be deadly, according to the American College of Obstetricians and Gynecologists. "There were a couple of little operations to fix all that, so that created a little hole in my uterus, which I think made it really tough to get pregnant again. It was a long road," she said. Kardashian West said that if the placenta grows deeper during this pregnancy, her uterus may have to be removed.

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Olivia Wilde

In April, our cover model told us what childbirth does to your lady parts. (Wilde gave birth to her son Otis in 2014.) She said: "First of all, you haven't seen your vagina in months, even though it's all her fault you're in this situation. Now that you can finally confirm that she is, in fact, still there, she isn't the gal that you remember, and would rather you back off and give her some space (and an ice diaper) for the time being, thank you very much." (She forgot to mention these other 4 Sex Saboteurs After Childbirth.)

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Jemima Kirke

Months before #ShoutYourAbortion was a trending hashtag, the "Girls" actress shared her story in a video for Draw The Line, a campaign by the Center for Reproductive Rights. In 2007, Kirke became pregnant with her boyfriend at the time. "My life was not conducive to raising a happy, healthy child. I just didn't feel it was fair," she said. She had an abortion at a Planned Parenthood in Rhode Island—and emptied her checking account to pay for the procedure, even opting to forgo anesthesia to reduce the price. "I've always felt that reproductive issues should be something that women especially should be able to talk about freely, especially amongst each other," she said.